<?php

/**
 * This is the model class for table "tag".
 *
 * The followings are the available columns in table 'tag':
 * @property integer $id
 * @property string $name
 * @property integer $frequency
 */
class tag extends CActiveRecord
{
	/**
	 * @return string the associated database table name
	 */
	public function tableName()
	{
		return 'tag';
	}

	/**
	 * @return array validation rules for model attributes.
	 */
	public function rules()
	{
		// NOTE: you should only define rules for those attributes that
		// will receive user inputs.
		return array(
			array('name', 'required'),
			array('frequency', 'numerical', 'integerOnly'=>true),
			array('name', 'length', 'max'=>128),
			// The following rule is used by search().
			// @todo Please remove those attributes that should not be searched.
			array('id, name, frequency', 'safe', 'on'=>'search'),
		);
	}
	public static function string2array($tags)
	{
    return preg_split('/\s*,\s*/',trim($tags),-1,PREG_SPLIT_NO_EMPTY);
	}
 
	public static function array2string($tags)
	{
		return implode(', ',$tags);
	}
	
	/**
	 * @return array relational rules.
	 */
	public function relations()
	{
		// NOTE: you may need to adjust the relation name and the related
		// class name for the relations automatically generated below.
		return array(
		);
	}

	/**
	 * @return array customized attribute labels (name=>label)
	 */
	public function attributeLabels()
	{
		return array(
			'id' => 'ID',
			'name' => 'Name',
			'frequency' => 'Frequency',
		);
	}

	/**
	 * Retrieves a list of models based on the current search/filter conditions.
	 *
	 * Typical usecase:
	 * - Initialize the model fields with values from filter form.
	 * - Execute this method to get CActiveDataProvider instance which will filter
	 * models according to data in model fields.
	 * - Pass data provider to CGridView, CListView or any similar widget.
	 *
	 * @return CActiveDataProvider the data provider that can return the models
	 * based on the search/filter conditions.
	 */
	public function search()
	{
		// @todo Please modify the following code to remove attributes that should not be searched.

		$criteria=new CDbCriteria;

		$criteria->compare('id',$this->id);
		$criteria->compare('name',$this->name,true);
		$criteria->compare('frequency',$this->frequency);

		return new CActiveDataProvider($this, array(
			'criteria'=>$criteria,
		));
	}

	/**
	 * Returns the static model of the specified AR class.
	 * Please note that you should have this exact method in all your CActiveRecord descendants!
	 * @param string $className active record class name.
	 * @return tag the static model class
	 */
	public static function model($className=__CLASS__)
	{
		return parent::model($className);
	}
	
	public function updateFrequency($oldTags, $newTags)
    {
        $oldTags=self::string2array($oldTags);
        $newTags=self::string2array($newTags);
        $this->addTags(array_values(array_diff($newTags,$oldTags)));
        $this->removeTags(array_values(array_diff($oldTags,$newTags)));
    }
 
    public function addTags($tags)
    {
        $criteria=new CDbCriteria;
        $criteria->addInCondition('name',$tags);
        $this->updateCounters(array('frequency'=>1),$criteria);
        foreach($tags as $name)
        {
            if(!$this->exists('name=:name',array(':name'=>$name)))
            {
                $tag=new Tag;
                $tag->name=$name;
                $tag->frequency=1;
                $tag->save();
            }
        }
    }
 
    public function removeTags($tags)
    {
        if(empty($tags))
            return;
        $criteria=new CDbCriteria;
        $criteria->addInCondition('name',$tags);
        $this->updateCounters(array('frequency'=>-1),$criteria);
        $this->deleteAll('frequency<=0');
    }
	public function findTagWeights($limit=20)
	{
		$models=$this->findAll(array(
			'order'=>'frequency DESC',
			'limit'=>$limit,
		));

		$total=0;
		foreach($models as $model)
			$total+=$model->frequency;

		$tags=array();
		if($total>0)
		{
			foreach($models as $model)
				$tags[$model->name]=8+(int)(16*$model->frequency/($total+10));
			ksort($tags);
		}
		return $tags;
	}
}
